federal charges that he and his olderbrothertamerlanplantedpressure cooker bombs near the finish line for the boston marathon. tamerlan later died after a shootout with police. in providence, rhode island, lawyers for tamerlan tsarnaev's wife catherine said she had been unaware of the bombing plot. >> the reports of involvement by her husband and brother-in-law came as an absolute shock to them all. as a mother, a sister, a daughter, a wife, katie deeply mourns the pain and loss to innocent victims, students, law enforcement officers, families and our community. in the aftermath of this tragedy she, her daughter and her family are trying to come to terms with this event. >> woodruff: meanwhile, both the "washington post" and the "new york times" have reported that the younger tsarnaev admitted his role in the attack. the "post" also reported he told investigators that u.s. involvement in the iraq and afghanistan wars were motivating factors. other accounts said there appeared to be no links to larger terrorist groups. in russia today, their mother said f.b.i. agents talked to her abou

oftamerlantsarnaev,after he spent six months in russia. senator diane feinstein, chairing the intelligence committee, said senior f.b.i. may testify tomorrow about why they did not pursue the matter further. i misspoke in that set-up piece. tsarnaev was read his miranda rights in his hospital room today. we're joined by a reporter who has been following developments closely. dina temple raston is npr as anti-terrorism correspondent. welcome to you. do we know how much or what investigators are learning from tsarnaev in the hospital so far? >> well, there's been very little that they've learnd because he can't really understand that he can't speak. he has a tube in his throat. he has some sort of a wound on his neck and his hand. apparently to his jaw. there's some question as to whether or not it was a self-inflicted wound. so as a result apparently they're writing notes back and forth. it's unclear if those notes are ra port building so he learns to trust these people who are trying to question him or where they're getting substantive information from him. >> brown: what can you tell us a